Background: Hearing impairment (HI) could be a risk factor for cognitive decline, but cognition could plausibly also affect psychoacoustic assessment of hearing with audiometry. We examined the temporal sequence of hearing and cognitive function among non-demented, community-dwelling older adults.
Methods: Hearing and cognition were assessed between 2012-2015 and two years thereafter in 313 non-demented participants aged ≥60 years in the Baltimore Longitudinal Study of Aging. Poorer hearing was defined by pure-tone average (PTA) of 0.5-4 kHz tones in the better-hearing ear. Cognitive measures with either visual or auditory inputs were Trail-making Test Part B (TMT-B), Digit Symbol Substitution Test (DSST), California Verbal Learning Test (CVLT) immediate recall, short-delay, and long-delay, Digit Span Forward/Backward, Benton Visual Retention Test, and Mini Mental State Examination (MMSE). We used linear regression models for cross-sectional associations at each time point and autoregressive, cross-lagged models to evaluate whether baseline HI (time 1) predicted cognitive performance two years after baseline (time 2) and vice versa.
Results: Cross-sectionally, there were no associations between poorer hearing and cognitive performance. Longitudinally, poorer hearing was associated with declines in CVLT immediate (β=-0.073, SE=0.032, p=0.024), short-delayed (β=-0.134, SE=0.043, p=0.002), long-delayed (β=-0.080, SE=0.032, p=0.012) recall, and Digit Span Forward (β=-0.074, SE=0.029, p=0.011).) from time 1 to time 2. Cognitive performance at time 1 did not predict change in hearing status at time 2.
Conclusions: Audiometric HI predicted short-term cognitive declines in both CVLT and auditory stimuli for attention.